1. Field of the Invention
The present invention relates to dental devices, and particularly to a stabilizing device for dental crowns that permits a user to measure a marginal gap between a crown and a model tooth structure.
2. Description of the Related Art
A dental crown is one of the most common treatments in dentistry. A crown is most effective if it closely resembles tooth structure and does not leave gaps between the edge of the crown and unprepared tooth structure. Any opening or marginal gap in this area will subject the tooth to plaque accumulation which can cause recurrent caries and gum disease.
Many techniques have been described in the literature for measuring the marginal gap. Such techniques include cementing the crowns on stone replicas of prepared teeth and viewing sections with a light microscope. Other techniques include replicating the gap between the crown and the prepared tooth with silicone material and measuring its thickness with light microscopy or computer generated tomography. However, these techniques involve many variables that may cause or lead to errors that ultimately do not reflect the true marginal gap.
A travelling microscope or a measuring microscope is a light microscope that measures linear distances between two points in a horizontal manner within an accuracy of 0.01 inch. It is considered one of the most reliable techniques of measuring marginal gap because it provides direct access to the marginal gap between the crown and a prepared tooth structure. However, there is a need to stabilize the crown/tooth assembly in a repeatable manner under the microscope. Typically, a silicone index is made to stabilize the assembly to enable measurement of one point in one aspect of the assembly. When another point is intended to be measured, a second silicone index is made and so forth. Usually the maximum number that can be achieved is about eight measurements per crown/tooth assembly. It has been reported and suggested that the minimum number of points to measure around the assembly should be fifty so that the mean marginal gap truly represents the actual gap. This is nearly impossible using the silicone index technique.
There is a need for a technique that allows for holding the crown tightly on a prepared tooth structure while allowing for rotation of the crown to measure as many points as required without resorting to numerous silicone indexes.
Thus, a stabilizing device for dental crowns solving the aforementioned problems is desired.